Tristan Wade was a middle-school practical joker with an endearing crooked smile who told everyone he wanted to be in the Army like his dad, a military policeman stationed near Tacoma, Wash.

Zack Shannon was playing Army in a cul-de-sac where his family lived in Florida. He'd break his ankle later that fifth-grade year on a neighbor's trampoline across the street.

They were little boys oblivious to the beginning of America's war in Afghanistan. Any notion they might be caught up in the violence to come was the furthest thing from their parents' minds.

But this would be the nation's longest war.

All three children - Barrett, 8, Tristan, 11, and Zack, 9 - would reach manhood as fighting churned on. Barrett's desire to challenge himself, Tristan's drive for excitement and Zack's love of all things military would draw each on separate paths toward war.

As the conflict in Afghanistan slogs through its 12th year, all three young men have given everything to a war growing longer as they grew up. Zack died in a Blackhawk helicopter crash March 11. Just days before his planned return home, Tristan was killed March 22 by an improvised explosive device. Another roadside bomb mortally wounded Barrett on April 17; he was removed from life support as his parents stood by four days later.

This Memorial Day, the nation remembers more than 4,500 Americans who died in the war in Iraq, where the U.S. role ended in 2011, and nearly 2,200 who lost their lives in the Afghanistan War, a conflict from which President Obama says he will withdraw most American troops next year.

Among those now fighting and dying are young people all but unaware when it all began.

'HE WAS MY ONLY SON'

With jug ears and a grin filling half his face, Barrett Austin was a boy in perpetual motion at age 8. He had an embrace for everyone.

"He was very loving," says his mother, Yolanda Austin, of the son she remembers as a sensitive child. "He would hug all his teachers."

The 9/11 attacks were like distant thunder for a boy busy skipping rocks in the creek down the hill or switch-hitting for the Little League Diamondbacks.

"He was aware, but not capable of really understanding," says his father, Curt Austin. "It was just, 'Bad people are attacking us,'" Yolanda says.

The couple - both electrical engineers who do safety analysis for major oil companies - raised their family amid pine, cedar and oak trees at the end of a winding country road. Barrett was the oldest of two children born to Yolanda. Curt has an older daughter from an earlier marriage.

It was impossible the war would last long enough to take Barrett and even if it did, he would never go, Yolanda reasoned. "We didn't have the draft in place," she says. "And if we did, he was my only son. He was the only one to carry on the family name - and those aren't drafted."

"We just wanted something else for him," Curt says.

But they never counted on a kind of internal lottery that leads certain young men and women to volunteer, a strain of patriotism particularly endemic to these Appalachian foothills where seven of 11 boys on Barrett's Little League team would join the military. After high school, he spent a year working at an automotive assembly plant.

One day, Barrett pulled his mother aside in the kitchen.

"His final thing to me was, 'Mom, I'm going to do this and I need you to support me. I want you to go down with me to the (enlistment) office. I'm going to do it regardless," she recalls.

That was November 2011. He enlisted a few weeks later. By last August, he had completed advanced training to become a combat engineer, a job his mother knew from researching on the Internet involved the dangerous work of uncovering roadside bombs.

Home on leave, Barrett married Heather Hooker, a young woman he met on Facebook. By this past March, he was on his way overseas, ready to put his training into action, his 18-year-old wife says.

"He was excited," Heather says.

Shortly after winning his stripes as a private first class, Barrett was driving an armored truck on patrol in Wardak province south of Kabul when insurgents attacked. A bomb exploded and he suffered massive head and chest trauma.

Before the Army flew his parents and his wife to a U.S. Army hospital in Germany, where he was brought from Afghanistan, they were told he had no brain activity and was on life support.

"It was without a doubt the longest journey I've ever had to take," Curt says. "The world was still whirling around us and we could hardly hold it together."

But they had the chance to say goodbye.

"His body was warm," Yolanda says.

"We got to touch him and smell him," Curt says.

Barrett had always been their "miracle child" because an elusive heartbeat early in Yolanda's pregnancy left both fearing the unborn boy would not survive.

"I said, 'Good Lord, if you just let me have my son, I'll give him back to you when the time comes,'" Yolanda recalls. "Little did I know it was going to be a short 20 years."

WANTING TO BE LIKE DAD

From the time he was 9, Tristan Wade told everyone that he wanted to be like his dad and enlist in the Army. The 9/11 attacks only made him want it more.

The second of four boys, Tristan was the only one to enlist. Their father, a military policeman, often invited his buddies to the house on weekends. Over beer and poker, they'd talk about their work.

"The boys were always hearing what was going on, so I think that opened their eyes up at a younger age," Daniel Wade says. Tristan heard the stories and wanted in.

On the morning of Sept. 11, 2001, they were living in Tacoma, Wash. The elder Wade, stationed at Fort Lewis, remembers lacing up his sneakers with the TV on. He looked up and saw a plane crashing into one of the World Trade Center towers. He thought it was an action movie, but it happened again, and he soon realized he was watching the news.

Within hours, he'd kissed his family goodbye and was on a transport plane for Washington, D.C. In more than a decade, he'd served all over the world, protecting military outposts in Kosovo, Afghanistan and Korea. Now he was protecting the Pentagon.

Tristan was 11. He never looked back.

A 98-pound daredevil, he took up skateboarding after the Army transferred the family to Hawaii. He soon had an endless series of spills and sprains. "It seemed like every time I turned around he was hurt," Wade says.

Tristan often dug his father's Army rucksack out of the closet, stuffing it full of supplies and marching up the side of the volcano behind their house. "He was really driven," his father says.

In high school, the 115-pound sophomore surprised everyone by trying out for the football team. He made the squad and played linebacker, safety, running back and even returned punts - any position that involved "speed, jumping, agility, not just brute force," Wade says. He'd soon help lead them to the state championship game - they lost, but just barely.

Pegged by an Army recruiter his senior year as a promising candidate, Tristan told him he wanted "a cool job." The recruiter rattled off a series job titles. When he got to "combat engineer," the boy asked what they did. "You make things go 'boom,'" he said.

"I want that job," Tristan told him.

In basic training right after graduation, he ended up at New Mexico's White Sands Missile Range, assigned to the 573rd Clearance Company, which disposed of improvised explosive devices (IEDs). After a tour in Iraq, he returned to White Sands.

He was out with friends one Saturday night, standing in the parking lot of a Las Cruces bar, when a pretty girl in a Pontiac G5 honked at him. Alisha Morales had seen him inside but didn't know how to get his attention.

They had their first date a month later, and a year later, to the day, they were married. They got matching tattoos that told their story - his on his stomach, hers on her hip. When they stood together, the tattoos read: "Beep â?¦ beep."

A month later, his unit deployed to Afghanistan. She sent him care packages - two a week - and they talked almost every day by Skype. "If he was off he'd talk to me all day," she says.

On March 21, just a few days before his unit was to come home, the couple had their usual Skype chat. He said he had "a weird feeling - he was just nervous," Alisha says. "It was his last mission so he just wanted to come home." The following day, an IED killed Tristan and wounded his interpreter.

'HE WAS THE BABY'

Kimberly Allison worried about the oldest of her four boys when the Twin Towers fell, the Pentagon's south face was demolished, a passenger jet crashed into the Pennsylvania countryside and war beckoned. Her oldest, Joe, then 20, was in Army boot camp. Her second son, Robert, then 18, had just finished Navy basic training.

"That was like, OK, this war is a little close to home," says Kimberly, who raised her boys in Dunedin, Fla., north of St. Petersburg.

Thank God, she was thinking, her other sons were so young. Steven, then 14, was in middle school. Zack, 9, was only in the fourth grade.

Zack caught images of the 9/11 tragedy on television in between playing Madden NFL video games. His passion: baseball cards (assembling an estimated 10,000 growing up).

"He was the baby," she says of Zack, certain the war would be over before he came of age. "Never thought it would drag on this long."

A critical care nurse whose marriage to Zack's father had ended, Kimberly remarried when the boy was an infant.

As the years passed, her oldest sons were spared. Joe never deployed. Robert became a submariner serving far from Afghanistan. Steven joined the Army National Guard to deploy in Kuwait.

But it was becoming clear that if the Afghanistan War lasted long enough, Zack would be more than ready.

He idolized his older brothers and their military service, wearing Joe's discarded fatigues trick-or-treating in fifth grade, complete with camouflage face paint. He devoured the History Channel, books on the Civil War, Saving Private Ryan and Band of Brothers.

"Zack used to say to me, 'Oh well, Joe, Robert and Steven went in. I guess I have to carry on the tradition,'" Kimberly says, "And I'm like, 'Oh, you don't have to.'"

Driving down Interstate 75 in the family Ford Expedition returning from visiting grandparents, Robert and Steven would vigorously debate the virtues of Army vs. Navy for a rapt younger brother. Kimberly didn't need to hear it. "I'd be like, enough already," she recalls.

Zack joined ROTC at Dunedin High School, insisting his mother maintain the vertical, military creases in his dress-white uniform shirt and inspecting himself in the hallway mirror before walking to school.

When he finally enlisted after graduation, Zack chose crew maintenance on a Blackhawk helicopter. He actually grew his last few inches during basic training, Kimberly remembers.

"I never would have dissuaded him," she says. "Not that I think could have."

Zack went to Afghanistan in December. His family was told he volunteered for a night mission March 11. Initial reports say the helicopter crashed in bad weather, killing all five on board, including Spc. Zachary "Zack" Shannon.

Kimberly got a call just as she was leaving work from her husband, Chip Allison, mysteriously urging her to come directly home but saying nothing more.

Her heart sank when she saw her son Steven's truck parked outside. An Army chaplain and casualty officer were in her living room, visible through the plate glass window.

"As soon as I got halfway up the driveway, I saw them standing there," Kimberly recalls. "And I knew."

EPILOGUE

It's been only a few weeks since Barrett Austin, Tristan Wade and Zack Shannon were laid to rest.

After burying her 23-year-old husband, Alisha Morales, only 24 herself, says it sometimes doesn't even feel like it's real. But on this Memorial Day, she's determined to let people know whom Tristan was and what he did.

"Everybody knows that he's a hero, and that's all I care that people know now," she says. "And I don't want that to just go away."